Method and Apparatus for Controlling an Operation Mode of a Mobile Terminal

1. A method for operating an electronic device, the method comprising: determining whether an input is received with respect to the electronic device for a first specified period of time while a display of the electronic device is operating at a first brightness; capturing an image using an image sensor operatively coupled with the electronic device when no input has been received with respect to the electronic device for the first specified period of time while the display of the electronic device operates at the first brightness; determining whether a specified object is recognized in the image; changing operation of the display of the electronic device from the first brightness to a second brightness when determining that the specified object is not recognized in the image, wherein a luminance of the display at the first brightness is greater than a luminance of the display at the second brightness; maintaining operation of the display at the first brightness when determining that the specified object is recognized in the image; determining whether an input is received with respect to the electronic device for a second specified period of time after the display of the electronic device is changed to the second brightness; and changing operation of the display of the electronic device from the second brightness to a deactivated state when no input has been received with respect to the electronic device for the second specified period of time.

2. The method of claim 1 , further comprising: capturing a second image using the image sensor after changing operation of the display from the first brightness to the second brightness; determining whether the specified object is recognized in the second image; and maintaining the display on when the specified object is recognized in the second image and no input is received with respect to the electronic device for the second specified period of time.

3. The method of claim 1 , further comprising: when changing operation of the display to the deactivated state, executing a lock state for the electronic device.

4. The method of claim 3 , further comprising: in response to detecting an event while the electronic device is in the lock state, displaying a lock screen; and releasing the lock state in response to detecting a specific user input when the lock screen is displayed.

5. The method of claim 1 , wherein changing operation of the display from the first brightness to the second brightness comprises: adjusting at least one of a brightness value, a gamma value, and a contrast value of the display.

6. The method of claim 1 , wherein when the operation of the display is changed to the second brightness or to the deactivated state, the method further comprises outputting at least one of a sound, a vibration, and a blinking light by the electronic device.

7. The method of claim 3 , wherein determining whether the specified object is recognized in the image comprises: determining whether a face is detected within the image.

8. The method of claim 7 , wherein the face is preregistered and stored in the electronic device.

9. The method of claim 7 , wherein determining whether the specified object is recognized in the image comprises: determining whether a user's gaze is oriented towards the display.

10. The method of claim 1 , wherein determining whether the specified object is recognized in the image comprises: determining whether at least one of an iris of a user and a movement of the iris is recognized in the image.

11. A mobile terminal comprising: a display; an image sensor; and a processor electrically coupled with the image sensor, the processor is configured to: determine whether an input is received with respect to the mobile terminal for a specified period of time while the display operates at a first brightness, capture an image using the image sensor when no input has been received with respect to the mobile terminal for the specified period of time while the display operates at the first brightness, change operation of the display from the first brightness to a second brightness when determining that a specified object is not recognized in the captured image, wherein a luminance of the display at the first brightness is greater than a luminance of the display at the second brightness, maintain operation of the display at the first brightness when determining that the specified object is recognized in the image, determine whether an input is received for a second specified period of time after the display is changed to the second brightness, and change operation of the display from the second brightness to a deactivated state when no input has been received for the second specified period of time.

12. The mobile terminal of claim 11 , wherein the processor is further configured to: capture a second image using the image sensor after changing operation of the display from the first brightness to the second brightness; determine whether the specified object is recognized in the second image; and maintain the display on when the specified object is recognized in the second image and no input is received for the second specified period of time.

13. The mobile terminal of claim 11 , wherein the processor is further configured to: when changing operation of the display to the deactivated state, execute a lock state.

14. The mobile terminal of claim 13 , wherein the processor is further configured to: in response to detecting an event while the mobile terminal is in the lock state, display a lock screen; and release the lock state in response to detecting a specific user input when the lock screen is displayed.

15. The mobile terminal of claim 11 , wherein the changing operation of the display from the first brightness to the second brightness comprises: adjusting at least one of a brightness value, a gamma value, and a contrast value of the display.

16. The mobile terminal of claim 11 , wherein when the operation of the display is changed to the second brightness or to the deactivated state, the processor is further configured to output at least one of a sound, a vibration, and a blinking light.

17. The mobile terminal of claim 13 , wherein determining whether the specified object is recognized in the image comprises: determining whether a face is detected within the image.

18. The mobile terminal of claim 17 , wherein the face is preregistered and stored in the mobile terminal.

19. The mobile terminal of claim 17 , wherein determining whether the specified object is recognized in the image comprises: determining whether a user's gaze is oriented towards the display.

20. The mobile terminal of claim 17 , wherein determining whether the specified object is recognized in the image comprises: determining whether at least one of an iris of a user and a movement of the iris is recognized in the image.